﻿using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        Form2 f2;
        Form3 f3;
        public Form1()
        {
            InitializeComponent();
        }

        private void toolStripMenuItem4_Click(object sender, EventArgs e)
        {
            if (f2 == null)
            {
                f2 = new Form2();
                f2.MdiParent = this;
                f2.Show();
            }
        }

        private void toolStripMenuItem3_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void toolStripMenuItem5_Click(object sender, EventArgs e)
        {
                f3 = new Form3();
                f3.MdiParent = this;
                f3.Show();
            
        }
    }
}
